A process of manufacturing a semiconductor device includes a process of forming a silicon-based insulating film such as a silicon oxide film (SiO2), a silicon nitride film (Si3N4), or the like, on a substrate such as a silicon wafer, i.e., an insulating film containing silicon, which is a predetermined element. The silicon oxide film is widely used as an insulating film or an interlayer film having a high insulation property and low permittivity. In addition, the silicon nitride film has a good insulation property, corrosion resistance, permittivity, film stress controllability, or the like, and is widely used as an insulating film, a mask film, a charge accumulation film, or a stress control film. Further, a technique of adding carbon (C) into the insulating film is also already known, and thus etching resistance of the insulating film can be improved.
However, while the etching resistance of the insulating film can be improved by adding carbon into the insulating film, permittivity may be increased to deteriorate a leak resistance. That is, while the insulating films have both merits and demerits, in the related art, there is no thin film having characteristics of low permittivity, high etching resistance, and high leak resistance.